body{
    width: 100%;
    height: 100vh;
    background: radial-gradient(circle pink 0%,white 25%,#FFFF00 50%,palevioletred 75%,blue 100%);
    margin: 0px;
    /*弹性布局：主轴方向居中，交叉轴方向居中*/
    display: flex;
    justify-content: center;
    align-items: center;    
}
div{
    text-align: center;
}
div>span:nth-child(1){
    font-size: 300px;
    display: inline-block;
}
div>span :nth-child(3){
    font-size: 40px;
}